#include<stdio.h>
#include<stdlib.h>
#include<time.h>

#define M_20m 20*1000*1000

void f1()
{
    int begin=clock();
    int *a=(int*)malloc(M_20m*sizeof(int));
    printf("f1 %d\n",clock()-begin);
}

void f2()
{
    int begin=clock();
    /**
        Here causes a Win32 fault,M_20m is too big that
        the stach is not enough, so an error.
    */
    ///int a[M_20m];//In defination, memory will be allocated.
    printf("f2 %d\n",clock()-begin);
}

void main()
{
    f1();
    f2();
    char c='c';
    char* a,*b;
    a=&c;
    b=&c;
}
